Leonardo da Vinci was the first man to suggest that growing trees add a new ring in their trunks each year. The 11 in these rings relates to the physical conditions which the tree experiences. Thus, trees grown in a 12 area and time each develop a pattern or configuration of their rings.
This 13 was of little significance until Andrew E. Douglas began to study tree rings in Arizona in 1900. Using a technique called cross dating, he was able to employ tree rings to the study of archaeological sites and date the ruins with 14 . Some were as old as 6700 B. C. ! This study of tree rings is called dendrochronology.
In time the cross dating was 15 by a carbon 14 process. This approach measured the amount of carbon 14 radiating from a piece of wood and 16 to determine the age of that wood. Further use of the carbon 14 technique has shown that the radiation process is more complex and less 17 than had been at first thought.
The most 18 aspect of tree ring research is now called
dendroclimatology. This 19 of the reconstruction of climates and climatic cycles and events from the evidence found in the tree rings. From this it is hoped that a 20 of drought cycles can be determined in the American Southwest. Such information will be of great help in determining the life and ecology of that region of the United States.
A. thus B. model C. variation D. concept
E. accuracy F. exciting G. consists H. given
I. proposition J. composes K. further L. pattern
M. supplemented N. reliable O. excellent
II. C 12. H 13. D 14. E 15. M 16. A 17. N 18. F 19. G 20. L
上一篇: 四级冲刺练习阅读(61)
下一篇: 四级冲刺练习阅读(25)
国内英语资讯:Economic Watch: China lifts investment quota limit for QFII, RQFII amid financial opening-up
中国游客最爱去哪儿旅游
国际英语资讯:Trump approval rating drops as expectations for recession, China trade concerns grow
国内英语资讯:Chinese premier exchanges views with U.S. entrepreneurs on trade
韩国客轮沉没导致数百人失踪
国际英语资讯:Israeli PMs annexation plan draws condemnation from Palestinian, Arab leaders
体坛英语资讯:2nd China Youth Games concludes in Taiyuan
体坛英语资讯:Gasquet advances into first Cincinnati semi
为什么要读名著:阅读经典名著能锻炼大脑!
自恋美少年爱自拍:自称“澳版帕里斯希尔顿”
英发廊用金正恩发型做广告 遭朝鲜官员警告
体坛英语资讯:Leipzigs 4-0 win spoils Union Berlins Bundesliga debut
似乎永不休止的感冒 为什么一直不见好转
《百年孤独》作者加西亚-马尔克斯去世
国际英语资讯:Sudans ruling council, armed groups closer to reaching peace deal
研究发现 女性更擅长情节记忆
全球最棒的18个书店:爱书的人绝不能错过
每天都是一首歌
体坛英语资讯:Berlin tie Bayern 2-2 in Bundesliga season opener
奖励辛苦工作的你:来一趟悠然假期吧!
现如今北京全球化程度已超华盛顿
华为5G基站出货量排名世界首位
香蕉姑娘吃水果减肥 最多一天吃51根香蕉
美翻了:哥斯达黎加间歇火山喷花瓣雨
国内英语资讯:Top political advisor stresses religious affairs management
国际英语资讯:ASEAN, China, Japan, S.Korea reaffirm commitment to multilateral trading system
国内英语资讯:Senior CPC official calls for contribution to mutual learning and benefit between China and
马尔克斯名言录:你跳过的舞只属于你
国内英语资讯:Xi meets representatives of outstanding units, individuals in education circles
华裔男子输光身家 曼哈顿大桥夹层中修建蜗居